Primary pulmonary hypertension: causes, symptoms, diagnosis, treatment

Primary pulmonary hypertension is the primary persistent increase in pulmonary artery pressure of unknown origin.

The disease is based on concentric fibrosis, hypertrophy of the pulmonary artery medial and its branches, as well as multiple arterio-venous anastomoses.

The cause and pathogenesis of primary pulmonary hypertension are unknown. In occasion of a pathogenesis there are 2 assumptions:

1. The disease is genetically conditioned, and its basis is a violation of the central regulation of vascular tone.
2. At the heart of the disease is the congenital or acquired disruption of the production of active vasoconstrictors: serotonin, endothelin, angiotensin II, with an increase in platelet aggregation and the formation of microthrombi in the microcirculatory bed of the lungs. Develops remodeling of pulmonary vessels.

Yu. N. Belenkov and E. Chazova (1999) distinguish 4 morphological types of primary pulmonary hypertension:

• plexogenic pulmonary arteriopathy - defeat of the arteries of the muscular type and arterioles of the lungs (the process is reversible);
• recurrent pulmonary thromboembolism - organic obstructive lesion of muscular arteries and pulmonary arterioles; thrombi of different prescription of the organization;
• pulmonary veno-occlusive disease - proliferation and fibrosis of intima of small pulmonary veins and venules, occlusion of precapillary vessels;
• pulmonary capillary hemangiomatosis - benign non-metastasizing vascular formations.

Symptoms of primary pulmonary hypertension

1. The most typical subjective symptoms are a feeling of suffocation even with a little physical exertion, fast fatigue, sometimes chest pains and palpitations, fainting, attacks of dizziness.
2. When examined - shortness of breath, pronounced diffuse cyanosis, absence of cough with phlegm, change of terminal phalanges in the form of "drumsticks" and nails - in the form of "watch glass".
3. Often there are hypertensive crises in a small circle of blood circulation (described in the article " Pulmonary heart ").
4. The objective symptoms of primary pulmonary hypertension are divided into two groups.

Signs of myocardial hypertrophy of the right ventricle:

• systolic pulsation of the right ventricle in the epigastric region;
• expansion of the border of cardiac dullness due to the right ventricle;
• ECG changes (see "Pulmonary heart");
• X-ray symptoms: protrusion of the outflow of the right ventricle - the pulmonary trunk in the right anterior oblique position of the patient. As the degree of hypertrophy of the right ventricle increases, the inflow pathway also changes, which leads to an increase in the right ventricular arc in the forward left oblique position. The ventricle approaches the anterolateral contour of the thorax, and its greatest convexity shifts toward the diaphragm, the acuity of the cardiac-diaphragmatic angle decreases. Signs of heart dilatation include an increase in the heart to the right and left, straightening of the cardiovascular and diaphragmatic angles. In the future there are signs of an increase in the right atrium as a result of the emerging relative insufficiency of the tricuspid valve. The right atrium protrudes anteriorly above the right ventricle arch in the left oblique position, in the forward position, an increase in the right atrium leads to an increase in the right transverse size of the heart;
• echocardiographic signs of an increase in the right ventricle. With the development of right ventricular failure increases the liver, there are swelling, ascites.

Signs of pulmonary hypertension:

• the emphasis of II tone on the pulmonary artery and its cleavage;
• percussion dilatation of the pulmonary artery;
• diastolic murmur over the pulmonary artery due to the relative insufficiency of the valves of the pulmonary artery;
• on the roentgenogram of the chest - protrude the trunk of the pulmonary artery, widening the main branches and narrowing the smaller ones.

5. The final diagnosis of primary pulmonary arterial hypertension is based on the results of cardiac catheterization, pulmonary artery and angiocardiopulmonography. These methods allow to exclude congenital heart disease, to determine the degree of hypertension of the small circle of blood circulation and overload of the right heart, to ascertain extremely high figures of total pulmonary resistance at normal pulmonary-capillary pressure. Angiopulmonography involves aneurysmally widened pulmonary artery trunk, wide branches of it, narrowing of arteries of peripheral lungs. Segmental branches of the pulmonary artery are, as it were, chopped off at a high degree of pulmonary hypertension, small branches are not visible, the parenchymal phase is not detected. The rate of blood flow is sharply reduced. Angiocardiography should be performed only in specially equipped X-ray operations with great care, since after the introduction of contrast medium, a pulmonary hypertensive crisis may arise, from which the patient is difficult to withdraw.
6. Radioisotope scanning of the lungs reveals a diffuse decrease in the isotope accumulation.

The program of examination for primary pulmonary hypertension

1. Common blood tests, urine tests.
2. Biochemical blood test: protein and protein fractions, seromucoid, haptoglobin, SRP, sialic acids.
3. ECG.
4. Echocardiography.
5. Radiography of the heart and lungs.
6. Spirography.
7. Cardiac catheterization and pulmonary artery.
8. Angiocardiopulmonography.
9. Radioisotope scanning of the lungs.

Treatment of primary pulmonary hypertension

Primary pulmonary hypertension is a disease of unknown etiology, characterized by a primary endothelial lesion, concentric fibrosis and necrosis of the walls of the pulmonary artery branches, which results in a sharp increase in pressure in a small circle of blood circulation and hypertrophy of the right heart.

Etiological treatment does not exist. The main principles of pathogenetic treatment are the following.

1. Limitation of isometric loads.
2. Active treatment of pulmonary infections.
3. Treatment with vasodilators:
   • treatment with calcium antagonists (usually used nifedipine, diltiazem). In the presence of sensitivity to calcium antagonists, 5-year survival is 95%, in its absence, 36%. If patients are sensitive to calcium antagonists, then with prolonged long-term therapy there is an improvement in the functional class and reverse development of right ventricular hypertrophy. Sensitivity to calcium antagonists is observed only in 26% of cases;
   • treatment with prostacyclin (progaglandin, produced by the vascular endothelium and having a pronounced vasodilating and antiplatelet effect) - is used to treat primary pulmonary hypertension that can not be treated by other methods. Treatment with prostacyclin leads to a persistent decrease in pulmonary vascular resistance, diastolic pressure in the pulmonary artery, improved survival of patients;
   • treatment with adenosine is carried out with a sharp increase in the pressure in the pulmonary artery (the so-called crisis in the small circulation), adenosine is administered intravenously in the form of infusion with an initial rate of 50 mcg / kg / min, increasing it every 2 min to the maximum effective. Reduction of pulmonary vascular resistance occurs on average by 37%. Thanks to a very short but powerful vasodilator action, a single adenosine administration is safe and effective.
4. Treatment with anticoagulants (in particular warfarin, in the initial daily dose of 6-10 mg with a gradual decrease under the control of partially activated thromboplastin time) leads to an improvement in the state of the microcirculation system, increases the survival of patients. Treatment with anticoagulants is performed in the absence of contraindications to their use (hemorrhagic diathesis, duodenal ulcer and stomach ulcer). There is a point of view about the greater expediency of treatment with antiplatelet agents (aspirin 0.160-0.325 per day for a long time).
5. Diuretic treatment is prescribed with a significant increase in pressure in the right atrium and manifestations of right ventricular failure.
6. Oxygen therapy is prescribed for severe hypoxemia.
7. When acute right ventricular failure is treated with dobutamine in a dose of 2.5 to 15 mcg / kg / min: 10 ml of solvent (5% glucose solution) are introduced into a bottle containing 250 mg of the drug powder, then everything is transferred to a bottle with 500 ml of a 5% solution glucose (in 1 ml of this solution contains 500 μg of the drug, in 1 drop - 25 μg).

[1], [2], [3], [4], [5], [6], [7], [8], [9]